Magnetic separator



April 6 1926. 'Y R. GREAVES MAGNETIC sEPARAro-R 3. 1923 2 Sheets-Sheet 1Filed March lpadv n April 6 1926.,

A R. GREAVES MAGNETIC SEPARATOB 'Filed March s, 1923 2 Sheets-snee*u 2FIG.

VPatented Apr. 6, 1926.

iszaasa UNITED STATES PATENT QFFICE.

ROBERT GREAVES, OF WALASEY, ENGLAND.

MAGNETIC sEPARATon.

Application -led March 3, 1923. `Ser1a1 No. 622,655.

To @ZZ whom it may concern: l

Be it known that I, ROBERT GnEAvEs, a

Vsubject of the King of Great Britain, and

resident vof lVallasey, Cheshire, England,

have invented certain new and useful Ini-v Yan electromagnet is arrangedin the floor of a chute over which vmaterial passes, from which materialparticles of iron are'to be separated.

According to the process of the present invention, the material iscaused to cascade over a series of magnets arranged in steppings, thetrailing ends of the armature or pole shoe of the electro-magnets beinginwardly bevelled or formed with upstanding shoulders so that particlesof iron which would tend to be carried along these surfaces Vby theflowing stream of material, will on reaching the sharp trailing edges orshoulders of the pole shoes, be caught under or lin the angle behindsaid pole shoes and be brought directly'out ofthe flowing stream ofmaterial.

Several types of apparatus for carrying out the invention areillustrated diagrammatically in the accompanying drawings in which Fig.l is an elevation and Fig. 2 a

plan of a separator the magnetic pole slices having undercut -orbevelled shoulders. Fig. 3 is a fragmentary elevation of a modified formof connecting the series of pole slices together and Fig. 4 is afragmentary elevation showing a form of pole shoe with a right-angledshoulder instead Vof an undercut edge.

In a preferred form of construction, Figs. l and 2, a number of magnetsl are arranged Yin sequence having their pole shoes 2, the

trailing edges 3 of which are bevelled at 4, arranged in sequence and ondifferent levels one above the other so that as the material falls bygravity over the edges 3 of said pole shoes in sequence, the particlesof metal passing over the trailing edges will be drawn under thebevelled edges 4, and this eEect will be increased by the magneticattraction of the next pole shoe in sequence.

The pole shoes may be spaced apartfrom one another by means ofnon-magnetic pieces. In the arrangement shown inffFigs. l and `2 thepole shoes forming One .Si'lface are spaced'apart by brass or gun metalchannel pieces 5 through which are passed pins 6 having tapered endswhich enter corresponding holes in the edges of the pole shoes. rIhepole shoes on one level are connected to those on a lower level bynon-magnetic brass or gun metal angle pieces 7, and the magnetic cores lare secured to the pole shoes 2 and to a common bridge bark 8 by screws9or otherwise. The coils are mounted round the magnetic cores l and are'energized in lany suitable manner.

In the alternative construction shown in Fig. 3 the pole shoes aremerely connected together by flat piecesv 5a of some non-inagneticmaterial, the arrangement being otherwise similar to'that shown inFig. 1. In Fig. 4- instead of the shoulders 4.-" being undercut they areformed square with the top surface of the pole shoes 2.

Vith such arrangements, the coils 10, being energized, the lines offorce from the pole shoes pass from a higher to a lower level across theundercut edge a of the shoulder et developing a strong magnetic fieldthroughout the full width of the chute round the angular cavity a.Consequently, as the flowing stream of material cascades over the poleshoes from a higher to a lower level any particles of iron which wouldotherwise tend to be carried along are drawn into the angular spaces aout of the path of the stream of material and are maintained there. Inorder to remove these separated particles of iron, the current isswitched olf the electro-inagnet coils cle-energizing the magnets andpermitting the particles of iron to be readily removed.

The action of such an apparatus is very effective in separatingparticles of iron by reason of the fact that as the lines of forceradiate from one shoe at a higher level to another at a. lower level andin the same direction as that in which the material is falling over thehigher shoe, the'particles are under magnetic action for a comparativelylong period while passing the cavities a and are, therefore, more likelyto be trapped therein.

It will be understood that any known means may be used for making thematerial traverse the apparatus, such as inclining the apparatus, suchas shaking means, or shaking means coupled with a suitable inclinationof the apparatus, l

I claim:

l. A magnetic separator' tor the extraetion of particles ot' iron orsteel Vtroni flowing loose material` comprising a series ot mag:- netsarranged one behind the other in stepped 'formation downward trom the'feeding-in end to the discharge end tor the material said steppedtoi-mation providing pockets for the collection and retention ot themagnetic particles7 at the bottoms ot which pockets the npper ends ot'the pole pieces are located.

Q. A magnetic separator for the extraetion of particles ot iion or steelfrom flowing` loose material con'iprisingv a series of magnets arrangedone behind the other in stepped formation downward from the feeding-inend to the discharge end tor the material. said stepped formationproviding pockets for the collection and retention ot the magneticparticles, at the bottoms ot which pockets the upper ends of the polepieces are located, said pole pieces having their tail ends undercut andVloi-minr the end walls ot the pockets.

3. AJ map'neiic separator vtor extracting particles ot iron or steeltrom loose material, comprising;l magnets.y arranged in series onebehind the other. each successive magnet having' its upper pole piece ina lower lint parallel plane relative'to the pole piece ot the precedingmagnet to provide a pocket formation steppingdownward vfrom the Feedingend to the discharge end ot the series, over which series the loosematerial is passed for the extraction ot the iron or steel particlesinto the pockets` at the hot toms of which pockets the upper ends ot thepole pieces ai'e located.

ln testimon)v whereof I allix in v signatnre.

ROBERT GlllitVlS.

